U.S. patent number 5,100,153 [Application Number 07/482,035] was granted by the patent office on 1992-03-31 for game using radio-controlled vehicles.
Invention is credited to Gregory A. Welte.
United States Patent |
5,100,153 |
Welte |
March 31, 1992 |
Game using radio-controlled vehicles
Abstract
The invention relates to a game using remotely-controlled
miniature vehicles. One player drives an invading vehicle which
shoots a ping-pong ball at a target which is defended by a second
player. The defender fires balls at the vehicle and, if he strikes
the vehicle, the vehicle incurs a penalty of temporary disablement.
In addition, the vehicle can be required to periodically tag bases
which the defender strews on the playing field; failing to do
inflicts a penalty. Further, the invader can fire two types of
missiles, and the defender must protect two goals. Firing the first
missile can act as a feint by which the defender is distracted from
defending one of the goals.
Inventors: |
Welte; Gregory A. (Champaign,
(Champaign County), IL) |
Family
ID: |
23914381 |
Appl.
No.: |
07/482,035 |
Filed: |
February 20, 1990 |
Current U.S.
Class: |
273/357; 124/29;
273/355; 273/359; 446/191; 446/88 |
Current CPC
Class: |
A63H
17/006 (20130101); A63F 9/02 (20130101) |
Current International
Class: |
A63F
9/02 (20060101); A63H 17/00 (20060101); A63H
017/045 (); F41J 009/02 () |
Field of
Search: |
;273/357,355,356,359
;446/454,455,456,435 ;124/29 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
Radio Shack 1990 Catalog 1-1990. .
Fordham 1990 Catalog 1-1990..
|
Primary Examiner: Grieb; William H.
Claims
I claim:
1. A game, comprising:
a) a target;
b) a vehicle which
i) is remotely controllable by a player; and
ii) includes means for shooting a projectile toward the target;
c) sensing means on the vehicle for sensing one or more of the
following events:
i) contact with a foreign object;
ii) proximity to a predetermined type of object;
iii) impingement of a predetermined type of radiation; and
d) penalty means for interfering with the player's control of the
vehicle in response to the event.
2. A game, comprising:
a) a target;
b) an invading vehicle which is remotely controllable by a first
player and includes means for shooting a projectile toward the
target;
c) one or more roving vehicles which roam in the vicinity of the
invading vehicle; and
d) one or more sensors on the invading vehicle for detecting
contact with a roving vehicle.
3. A game according to claim 2 and further comprising:
e) penalty means, on the invading vehicle, which imposes a
performance penalty in response to contact with a roving
vehicle.
4. A game according to claim 3 and further comprising:
e) a self-propelled slug vehicle which advances toward a goal, and
which stops in response to contact with the invading vehicle.
5. A game according to claim 3 and further comprising:
e) a self-propelled slug vehicle which advances toward a goal, and
which temporarily reverses its advancement in response to contact
with the invading vehicle.
6. A toy, comprising:
a) a vehicle which is remotely controllable by an operator;
b) a sensor on the vehicle for sensing a collision with a
projectile; and
c) penalty means associated with the sensor for interfering with
the operator's control of the vehicle in response to said
collision.
7. A toy according to claim 6 and further comprising:
c) a cannon on the vehicle for shooting a projectile.
8. A game comprising:
a) an invading vehicle which is remotely controllable by a first
player, and which includes:
i) a gun which shoots a projectile;
ii) a sensor for sensing a strike on the vehicle by a missile;
iii) a sensor for sensing a collision with another vehicle; and
iv) penalty means for responding to the sensors and temporarily
interfering with control of the vehicle in response;
b) one or more targets for the gun;
c) one or more guns which are aimed by a second player and which
shoot said missiles at the vehicle; and
d) a slug vehicle which advances toward a goal, and which suspends
advancement in response to contact with the invading vehicle.
9. A toy, comprising:
a) a toy vehicle;
b) means for
i) receiving radiated signals from a remote operator and
ii) controlling movement of the vehicle in response to the received
signals; and p1 c) a cannon on the vehicle which shoots a
substantially hollow ball.
10. A toy according to claim 9 and further comprising:
c) a sensor on the vehicle for sensing a collision with an object;
and
d) penalty means for interfering with the operator's control of the
vehicle in response to a sensed collision.
11. A vehicle according to claim 9 and further comprising:
c) means for allowing the remote operator to fire the cannon.
12. A game, comprising:
a) a toy vehicle, which includes:
i) means for
A) receiving radiated signals from a remote operator and
B) controlling movement of the vehicle in response;
ii) a cannon which shoots a substantially hollow ball;
b) a plurality of bases which can be placed at selected locations
by a player; and
c) means for interfering with control of the vehicle if the vehicle
fails to periodically tag a base.
13. A game, comprising:
a) first and second self-propelled toy vehicles, the first being
small enough that the second can roll over it;
b) a sensor on the second vehicle for sensing contact with the
first vehicle;
c) means on the first vehicle for altering movement of the first
vehicle in response to said contact.
14. An amusement system, comprising:
a) a first self-propelled vehicle;
b) a second self-propelled vehicle of height no greater than
approximately the axle height of the first vehicle, and
including:
i) means for sensing contact with the first vehicle and providing a
contact signal in response.
15. A system according to claim 14 and further comprising:
c) a system on the second vehicle for responding to the contact
signal and altering movement of the second vehicle in response.
16. A toy, comprising:
a) a miniature self-propelled vehicle;
b) a gun for shooting a projectile; and
c) a sensor for detecting contact with incoming missiles, and
firing the gun in response.
17. Apparatus according to claim 16 and further comprising:
c) means for causing the gun to shoot following release of the
vehicle by a player.
Description
The invention concerns remotely controlled miniature vehicles which
shoot a ball toward a goal, while being fired upon by a goal
defender.
BACKGROUND OF THE INVENTION
Remotely controlled miniature vehicles are well known, and some
have achieved a high degree of sophistication. For example, such
vehicles can achieve very high speeds, and have suspension systems
and knobby tires which allow them to drive outdoors on dirt or
cinder tracks.
Vehicles of this type offer friendly competition between players.
They also present an entertaining challenge to hand-eye
coordination.
OBJECTS OF THE INVENTION
It is an object of the invention to provide a game which involves
remotely controlled vehicles.
SUMMARY OF THE INVENTION
In one form of the invention, a player has a radio-controlled
vehicle which must successfully run a gauntlet in order to attain a
position from which it can shoot a lightweight ball into the
defender's goal. While running the gauntlet, the vehicle is
bombarded by one or more weapons, such as balls or light beams,
shot by the defender. When the vehicle is struck, it suffers the
penalty of temporary disablement.
In another form of the invention, the defender has a low-slung
vehicle which automatically creeps, slug-fashion, toward a goal.
The invader can temporarily stop the march of the slug, or briefly
reverse the march, by running over it. If the slug reaches the goal
before the invader knocks out all the defender's targets, the
defender wins the round.
In another form of the invention, the defender has two goals, and
the invader carries another weapon in addition to the ball. The
second weapon is a heavy ball, or a self propelled vehicle, which
the invading vehicle propels along the ground toward one of the
goals. This attack distracts the defender, allowing the invader to
more easily attack the second goal.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 illustrate views of the invention in action.
FIG. 3 is a schematic view of the invading vehicle 3.
FIG. 4 illustrates a timer for firing the PING-PONG ball of FIG. 3
after an interval.
FIG. 4A illustrates the decaying voltage of the discharging
capacitor of FIG. 4.
FIG. 5 is an alternate circuit for providing the time interval of
FIG. 4.
FIG. 6 illustrates an apparatus which can be retro-fitted to an
existing miniature vehicle.
FIG. 7 illustrates sensors on the vehicle 3 for detecting
mines.
FIG. 7A is a cross-sectional view, taken from the side, of a shroud
which allows the mine sensors to slide across a carpet without
snagging.
FIG. 8 illustrates a sensor on the vehicle 3 for detecting IR
pulses.
FIG. 9 illustrates a sensor on the vehicle for detecting a strike
by a PING-PONG ball.
FIG. 10 illustrates one approach to mounting the flag 90 in FIG.
9.
FIGS. 11 illustrates the fact that a change in pitch of the vehicle
3 can cause false triggering.
FIG. 12 illustrates how the magnet 92 in FIG. 9 prevents false
triggering.
FIGS. 13 and 14 illustrate two types of penalty circuits 78 in FIG.
6.
FIG. 13A illustrates a sensor for detecting the capture of a
PING-PONG ball.
FIG. 15 illustrates a magnetic mine.
FIG. 16 illustrates a particular type of magnetic mine.
FIG. 17 illustrates an apparatus for optically detecting a strike
by a PING-PONG ball.
FIG. 17A illustrates an apparatus for acoustically sensing a strike
by a PING-PONG ball.
FIG. 17B illustrates a transparent fairing for a miniature vehicle
which acts as the target 132 in FIG. 17A.
FIG. 18 illustrates the operation of rover vehicles 142 which
induce penalties in the invading vehicle 3 if the former strike the
latter.
FIG. 19 illustrates touch sensors which sense contact of the rover
vehicles.
FIG. 20 illustrates an apparatus for disabling a rover vehicle in
response to capture of a PING-PONG ball.
FIG. 21 illustrates a slug vehicle, which temporarily reverses
direction when the invading vehicle (not shown) rolls over switch
164.
FIG. 22 illustrates a circuit for terminating power to, and
reversing direction of, the slug vehicle in FIG. 21.
FIG. 23 illustrates the use of an oval goal 33 which accommodates
different errors in shooting the PING-PONG ball, depending on the
shooter's orientation.
FIG. 23A illustrates that the cannon 5 is adjustable in
inclination.
FIG. 24 illustrates a microprocessor on the invading vehicle 3
which can sense collisions and inflict penalties in response.
FIG. 24A illustrates selection of different currents for the cannon
5 in order to alter muzzle velocity.
FIG. 25 is a flow chart illustrating one form of operation of the
microprocessor of FIG. 24.
FIG. 26 illustrates a bumper 310 which kicks a PING-PONG ball along
the ground.
FIGS. 27A and 27B illustrate multiple cannons and a cannon bearing
a magazine, respectively.
FIG. 28 illustrates an addition to the invading vehicle 3, namely,
a solenoid 358 which can shoot a golf ball 356 along the
ground.
FIG. 29 illustrates a variant of FIG. 28, in which the invading
vehicle carries a self-propelled attack vehicle which is launched
against the defender.
FIG. 30 illustrates a two-pronged attack by the invading vehicle:
first, the golf ball 356 is fired; next, the PING-PONG ball 29 is
fired.
FIG. 31 illustrates a two-pronged attack in which the invader first
launches a self-propelled vehicle 375.
FIG. 32 illustrates a mechanism for remotely firing a PING-PONG
ball.
DETAILED DESCRIPTION OF THE INVENTION
General Description
A player has a radio-controlled vehicle which tries to attain a
position from which it can shoot a ball into a defender's goal, or
knock down the defender's targets. While attacking, the vehicle is
bombarded by one or more weapons, such as balls or light beams,
shot by the defender. When the vehicle is struck, it suffers
temporary disablement.
The defender has several defensive weapons. First, the defender has
mines 21 in FIGS. 1 and 2 which temporarily disable the attacking
vehicle, inflicting a performance penalty. Several different types
of performance penalty are possible: (1) the vehicle may be forced
to drive in circles uncontrollably; (2) the power supply to the
vehicle can be periodically interrupted, so that vehicle motion
becomes erratic and hard to control; (3) the vehicle can be forced
to stop dead; (4) the vehicle can be forced to continue to drive at
high speed, perhaps in a randomly selected direction, thus driving
to an undesirable shooting position; (5) the vehicle can be forced
to prematurely shoot the ball; or (6) any combination of the
preceding. In general, the performance penalty impedes progress in
scoring goals.
A second defensive weapon is an infrared light gun 23. The gun
defines a line 24 which the vehicle cannot cross: the gun protects
territory. If the vehicle crosses the line, a sensor (later
described) on the vehicle triggers a performance penalty, similar
to those described above. The gun may fire at intervals, as
indicated in FIGS. 1 and 2, allowing the vehicle to dash across the
firing line when the gun is not firing.
A third defense lies in stationary cannons 25 in FIGS. 1 and 2,
like the ones on the vehicles. The vehicle 3 has a target (later
described) which detects ball strikes, and triggers a performance
penalty in response. It may be desired to manually toss the
PING-PONG balls, or to use hand-held guns.
Screens can be provided behind which the invading vehicle can hide.
The defender can also have screens behind which he can hide his
weapons, so that the invader does not know where the weapons are
aiming. The screens provide surprise and also allow for bluff
play.
For example, in FIG. 1, the invading vehicle 3 can maneuver toward
either position 6 or 9 if he is behind screen 12, without being
seen by the defending player 13. The defender 13 must speculate as
to where the invading vehicle 3 will pop up. Similarly, the
invading player 15 cannot see where the defender's cannons are
aiming. The defender can bluff by refraining from firing his
weapons when the invader pops up, thus tricking the invader into
believing that a given position is unprotected.
The purpose of the game is to score as many points as possible,
while trying to inflict as many penalty periods on the opponent as
possible.
In one variation, the invading vehicle does not try to avoid mines,
as above, but, instead, he is required to run over a mine
periodically in order to avoid a penalty. In this variation, the
defender exercises some control over the invader's movements.
In another variation, independent roving vehicles travel about the
playing field. A collision between the invading vehicle and a rover
causes a penalty.
In another variation, the invading vehicle is microprocessor
controlled.
More Detailed Description
FIG. 3 shows a radio-controlled vehicle 3, controlled by a radio
control 4, which carries a cannon 5 in the form of a solenoid 25
whose plunger 27 strikes a PING-PONG ball 29 supported by a cradle
32. Applicant has successfully used a solenoid from a doorbell
manufactured by the NuTone Corporation, Cincinnati, Ohio, and
powered by three six-volt batteries in series. During play, the
invading player 15 in FIG. 1 attempts to shoot the ball 29 into a
goal 33, such as a wastebasket about one foot high and eight inches
in diameter. Alternately, the invader tries to knock down targets
33A.
To use the cannon, a player loads his ball, sets a timer (described
later), and embarks on a scoring drive. The timer determines the
moment of cannon firing. (A switch 31 in FIG. 3 in the cannon can
sense the presence of the ball and set the timer, thus eliminating
the timer-setting step, and thus speeding up the play action. One
such switch is an optical proximity sensor, such as Omron
Photomicrosensor Model No. EE-SB5V, Cat. No. E56-E3-2, available
from Digi-Key Corporation, Thief River Falls, Minn.)
With a timed cannon, the player must ensure that the vehicle 3 is
positioned properly at the instant of firing, while avoiding the
defender's weapons during the drive to this position. It is
believed that this pre-set firing time will create a more
interesting game than allowing a player to fire at will. Further,
the pre-set time eliminates the need for an added communication
link from the player to his vehicle. However, to the contrary, some
players may prefer to fire their cannons remotely, at times
selected by them. It is known in the art how to use transmitter 4
in FIG. 3 to fire the cannon. For example, transmitter 4 can be of
type FP-4FG, 4ch, available from Futaba Corporation of America, 555
West Victoria Street, Compton, Calif. The transmitter can activate
one of the servo mechanisms which Futaba supplies. The
servomechanism closes a switch (not shown) which triggers the
solenoid which strikes the PING-PONG ball.
Timing Devices for Cannon
There are numerous timing devices for providing the time delay. For
example, in FIG. 4, after the player loads his ball, he presses and
releases switch 40. Upon release, capacitor 42 discharges through
resistor 44, giving a voltage plot as shown in FIG. 4A. The
capacitor 42 is connector to a comparator 46, such that when the
capacitor's voltage falls below the comparator's reference voltage,
on line 48, the comparator's output changes state, triggering a
one-shot 50, which applies a brief voltage pulse 51 to a Darlington
52. The Darlington 52 supplies current to the cannon solenoid 25,
thus firing the PING-PONG ball 29. At this time, the cannon can be
re-loaded, and the firing sequence can be repeated. The timing
interval is determined by the RC time constant.
Alternately, the components located to the left of dashed line 54
in FIG. 4 can be replaced by those in FIG. 5. The switch 40 flips
flip-flop 56, which sets the enabling input of a counter 58, which
starts counting. A digital comparator 60 compares the counter's
output 62 with a reference binary number on bus 64, and when the
former reaches the latter, provides an output signal 66 which
triggers the Darlington 52 in FIG. 4. When the count provided by
the counter 58 next changes, the output signal 66 will be driven
LO, as indicated. The timing interval between the closure of switch
40 and firing is determined by the clock frequency, the number at
which the counter 58 starts counting, and the binary number on line
64.
In addition, there are mechanical timing- and firing devices
available as well, known in the art. For example, a rotary kitchen
timer (not shown) can be easily adapted to trigger a cocked
mechanism which fires the cannon. Also, if the vehicle is
microprocessor-controlled, as described later, the timing involves
simple programming stems.
Defender's Stationary Cannons
The defender's stationary cannons 25 in FIGS. 1 and 2 can be
identical to those on the vehicle, with the exceptions that (a)
each stationary cannon can be given a different time interval, (b)
the stationary cannons are aimed independently, or (c) the
stationary cannons can be activated at will by switches under the
control of the defender. In the former two cases, the defensive
player aims each cannon at a position where he predicts the vehicle
will be located at the respective cannon's firing time. Then, as
the offensive vehicle runs the gauntlet, along dashed line 64 in
FIGS. 1 and 2, the cannons fire in sequence, striking the vehicle
if they are properly aimed. Mines, and other obstacles, later
discussed, can be positioned to require that the invading vehicle
follow a fixed path, which may force the invader into a bottleneck,
as shown in FIG. 1. (Lines B--B indicate the bottleneck, at which
the invader has difficulty maneuvering.)
It is possible that the electrically fired cannons will provide a
more interesting game than mechanical types, especially when, as
stated above, a switch senses the loaded ball and automatically
fires the cannon an interval later. One reason is that it is
envisioned that an invading vehicle will sometimes successfully
evade strikes by all stationary cannons, and then freely approach a
good shooting position. At this moment, the defender would like to
rapidly scoop up balls and re-load his cannons. The loading and
cocking of mechanical cannons would probably present an
unacceptable time delay, while the all-electric cannons would be
faster.
Penalty Circuit
The several penalty-inducing events (eg, mine strikes, infrared
cannon hits, and PING-PONG ball hits) each feed a signal to an OR
gate 70 in FIG. 6. The output of the OR gate triggers a one-shot
72, which switches on a relay 74 by means of transistor 76. The
one-shot 72 keeps the relay ON during the one-shot's pulse 77. The
relay is biased such that, in the absence of applied current,
normal operating control prevails. The pulse 77 may be viewed as a
penalty flag.
The relay 74 disconnects the normal control system of the Vehicle's
motors, such as propulsion motors and steering motors. The relay
substitutes a penalty circuit for the normal control system, which
assumes partial or full control of the vehicle for the penalty's
duration. Several types of penalty circuit are later discussed, as
are the particular penalty sensors on the vehicle.
Mines
In addition to cannons, each player has mines 21 in FIGS. 1 and 2
for penalizing the invading vehicles. The mines can be magnetic.
One type of circuit for sensing when the vehicle 3 runs over the
mines is shown in FIG. 7.
To sense the mines, each vehicle 3 has a magnetically sensitive
reed switch 79 which connects to the OR gate 70 in FIGS. 6 and 7.
When the reed switch is closed by a mine, it produces a proximity
signal which drives the OR output HI temporarily, giving control of
the vehicle to the penalty control circuit, as discussed above.
Alternately, the mines can be shiny objects, such as sheets of
aluminum foil or of corner cube reflectors, which are sensed by
optical sensors on the invading vehicle, such as the sensors
discussed above.
Infrared Light Gun
As another weapon, the defender has an infrared light gun 23 in
FIGS. 1 and 2, which strikes an infrared detector on the vehicle,
as shown in FIG. 8. Since ambient light contains infrared
frequencies, it may be desirable to flash (or modulate) the
cannon's light at a known frequency, and for the detector to
respond only to such flashing frequencies, and not to ambient
light. Such systems are commonly used in remote controls for
televisions.
One modulation system is shown in FIG. 8. The receiver 81 is
available as part number GPIU52X, catalog number 276-137, from
Radio Shack.RTM., Tandy Corporation, Fort Worth, Tex. The
transmitter, or IR gun 23, is essentially a 555 timer running at a
frequency matched to that required by the receiver. Instructions
for constructing such a transmitter-receiver pair are published by
Tandy Corporation, and one such set of instructions is attached
hereto as Table 1, and made a part hereof.
In general, firing the infrared cannon shoots a train of light
pulses. The receiver is sensitive to the infrared light, but only
when received as a train at a specified pulse frequency. Ambient,
interfering infrared light is filtered out.
Sensing Strikes on Vehicle
For sensing strikes by the PING-PONG ball, each vehicle may be
equipped with a strike sensor, as shown in FIG. 9. The sensor may
be a mechanical flag 90 which produces perceptible displacement
when struck by a PING-PONG ball 29: the ball 29 tilts the flag 90
to phantom position 90P. Preferably, the flag is supported at two
pivot points 92 in FIG. 10, which define an an axis which passes
through its center of gravity CG. With such a support, bouncing of
the vehicle itself, which occurs as the vehicle moves, will not
tend to trip the flag: the CG is driven up and down as bumps are
experienced.
However, if the vehicle changes drastically in pitch, false
indications of a ball strike may occur. As shown in FIG. 11, when
the vehicle rolls over a bump, the flag, when pivoted as described
above, will tend to remain in its previous orientation, as shown.
The sensor senses displacement of the flag, and falsely indicates a
ball strike.
A magnet, shown in FIGS. 9 and 12, which is fastened to the vehicle
and never contacts the flag, can gently bias the flag in position
so that the flag follows changes in pitch, as shown in FIG. 12.
With the magnet in FIG. 12, false indications are reduced.
The distance between the magnet and the flag 90 can be adjusted by
screw 97 in FIG. 9, thus altering the holding power of the magnet
and the sensitivity of the flag 90.
Flag-tripping can be sensed by the players themselves, or by
optical proximity sensors of the kind described above, and leading
to the OR gate, thus inflicting a performance penalty.
An alternate target may take the form of a basket 107 in FIG. 13A,
which funnels a received ball down to its neck 108, where the
presence of the ball is detected. The detection can be done by a
mechanical switch, or optically. When a ball strike is detected, a
penalty is imposed, as above, by a signal sent to the OR gate
70.
The basket need not take the form of a funnel, but may be a
container on the vehicle, such as the bed of the pick-up truck 3 in
FIGS. 1 and 2. Again, the ball's presence can be detected
optically, by a broken light beam. It may be desirable to provide a
resilient material, such as rubber foam, on the bed of the truck or
in the funnel, in order to prevent the ball from bouncing out as it
enters.
Another alternate is to position light sources 120 on one side of a
hoop 122, as in FIG. 17, and photo sensors 124 on the other side.
When a ball 29 passes through the hoop 122, one or more sensors
will momentarily register a drop in received light. If the outputs
are all ANDED together, in AND gate 127, a flip-flop 129 (or
Schmitt trigger) connected to the AND gate will be tripped, causing
the penalty. Termination of the penalty flag will re-set the
flip-flop, by the signal on line 132. Invertor 134 inverts the
signal, applying a HI signal when the penalty terminates. Diode 136
provides isolation.
Sensing the strike of the PING-PONG ball can be done acoustically.
In FIG. 17A, a sheet of hard, transparent material, such as that
used in making box-like picture frames, acts as a target 132. A
common microphone, labeled MIKE, is glued to the target, and feeds
an amplifier, AMP. The amplified signal is quite chaotic, since the
target has no single resonant frequency. Nevertheless, when one or
more signal components exceed the threshold defined by variable
resistor 299, the comparator COMP triggers the Schmitt trigger,
SCMMITT, which feeds a signal to OR gate 70.
One advantage of using a transparent target is that it can be
formed into the shape of a fairing 144 and attached to the hood of
an existing vehicle, as in FIG. 17B. With this retro-fitting, the
vehicle need not be redesigned, and the visual appeal of the
original vehicle remains unaffected. Further, different targets of
different size can be provided, and the user can interchange them
in order to adjust the level of difficulty of the game.
Penalty Examples
First, the penalty circuit can simply terminate power to the motors
for the penalty interval. In this case, the penalty line 110 in
FIG. 6 leads to ground. (This configuration presumes dc motors are
being used.) The vehicle is immobilized during the penalty period.
During immobilization, to keep the player's interest, a signal on
the vehicle can indicate the remaining duration of the penalty. For
instance, a display 137 in FIG. 3 can exhibit the actual time
remaining in the penalty.
It may be desirable to suspend the cannon timer in FIGS. 4 and 5
during this (or any other) penalty interval. Otherwise, the cannon
(if fired by the elapse of a time interval) can fire during the
penalty period, and the invader must return and re-load. This
suspension can be accomplished by connecting the penalty flag 77 in
FIG. 6 with an enabling pin of the cannon's clock in FIG. 5, thus
suspending the count-down while the penalty flag is HI. (Of course,
an invertor will be required if a LO signal is required to disable
the clock.) Alternately, if a capacitor circuit is used, as in FIG.
4, the penalty flag 77 can hold the capacitor's voltage HI (as by a
diode 141 connecting between flag 77 and the capacitor) until the
penalty is over, at which time the capacitor begins to discharge in
the usual manner. In this case, the penalty flag acts to reset the
switch 40, starting the timing interval over. Alternately, if the
cannon is remotely controlled, it may be desirable to allow the
invader to fire the cannon at this time.
As a second penalty example, the penalty control system can invert
the polarity of the voltage applied to the vehicle motor, thus
causing the vehicle to run in the opposite directions expected. The
invading player must compensate for this reversal in his driving.
Similarly, the penalty circuit can apply opposite polarity to the
steering motor, which causes opposite turns to those expected.
As a third example, the penalty control can be as shown in FIG. 13,
wherein a clock constantly opens and closes a relay 117, which
cycles the power supply to the vehicle's motor on and off. This
power cycling will make the vehicle operate jerkily, when relay 74
in FIG. 6 connects to penalty line 110.
Alternately, line 118 can be connected to a reverse polarity power
supply, as in FIG. 14, which will cause the vehicle to jerk forward
and backward as the relay opens and closes.
As a fourth example, the penalty control 78 in FIG. 6 can affect
the steering system of the vehicle. The penalty control can bias
the steering to the left, for example, thus forcing the vehicle to
run in circles. Alternately, the penalty control can alternately
bias the steering left and then right, forcing the vehicle to
"waddle," causing another type of loss of control.
As a fifth example, the penalty signal 77 in FIG. 6 can prematurely
fire the cannon, causing a lost shot. Line 120 in FIG. 4 shows
this.
Alternate Mine Detection
Instead of using reed switches, Hall effect sensors can be used to
detect the mines. Such sensors have the advantage of being able to
discriminate between different polarities of magnetism. For
example, with a north pole of a magnet pointing upward, a given
Hall effect sensor will produce a given voltage polarity (e.g.,
positive) when the vehicle is running east-to-west. The sensor will
produce an opposite polarity (negative) when the vehicle reverses.
(The voltage is determined by the equation F=qv.times.B, wherein F
is the force on an electron, q is the charge on one electron, v is
the velocity of the electron, and B is the magnetic flux density. V
is the sum of the drift velocity of the electron and the vehicle's
speed. When the vehicle reverses, v can reverse in sign, thus
inverting F.) The sensor will also produce the opposite polarity
when crossing the south pole, when running in the west-to-east
direction. These facts can produce several interesting variations,
two of which are the following.
First, if the vehicle is sensitive to only one polarity, the mines
can be rendered active or inactive merely by inverting them
physically. (This can be advantageous if each player has a vehicle:
his vehicle will not be sensitive to his own mines.) A defender can
be equipped with several mines, only some of which he makes active.
The inactive mines act as decoys, and the invader invader must
detect the decoys by trial-and-error.
Second, a mine can trigger a penalty when the vehicle crosses in
one direction, but not in the other direction. Thus, a given mine
can be dangerous on a scoring drive, but not on a retreat.
An induction coil can also be used to detect magnetic mines. Also,
the mines can be merely metallic. These can be detected by grid-dip
meters, which are themselves used in many types of "metal
detectors."
The mine sensors can be protected by a hemispherical shroud 81A in
FIG. 7A. This shroud will allow the sensors to be dragged along a
carpet or through grass without snagging. It is desirable for the
sensors to be brought as close as possible to the mines 21 for good
detection, but carrying the sensors low to the ground can cause
snagging.
Another Form of Invention
In another form of the invention, the invading vehicle 3 in FIG. 18
carries a cannon as described above. In addition, there are one or
more roving vehicles 142. The rovers 42 run in circles,
figure-eights, or randomly, and act as obstacles for the invading
vehicle. The invading vehicle has touch sensors along its sides,
which sense a collision with the roving vehicles. A collision
causes a penalty. One type of collision sensor is shown in FIG. 19,
wherein a bar 145 connects to a switch 147. Contact with the bar
triggers the switch and prompts OR gate 70 to produce a signal.
The rovers 142 can be inactivated by a strike with a PING-PONG
ball. One sensor for detecting a strike is like that shown above in
FIG. 13, and is also shown in FIG. 20. A funnel 153 on the roving
vehicle channels an incoming ball 29 to a neck, where an optical
proximity sensor 151 detects the ball, and terminates power to the
rover, as by turning off power transistor 157. Power to the motor
159 is thereby terminated.
If the rovers move randomly, then it is possible for them to move
out of the zone of play. To prevent this, the playing field can be
bounded by a barrier, such as a garden hose. The rovers cannot
surmount the hose, but the wheels of the invading vehicle 3 are
large enough so that it can do so. The invader is required to shoot
from within the field, where he is subject to attack by the rovers.
Of course, if the rovers run in circles, they will remain within a
confined area, and the hose is not needed.
In addition, the defender has a low-slung, slow-moving vehicle 162
in FIG. 21 which he activates at the beginning of a round of play,
and points toward a goal. This vehicle may be called a "slug,"
because of its slowness. If the slug reaches the goal before the
invader has knocked down all targets, the defender wins the
round.
The invader can temporarily stop the march of the slug by running
over it, or "stomping" the slug. A circuit for causing the stoppage
is shown in FIG. 22. Switch 164 triggers a one-shot 167, which
turns off power transistor 171 for the duration of pulse 169. (A
time delay may be desired so that the slug does not start moving
until the invading vehicle rolls away, and is not then resting on
the slug.)
Further, it may be desirable that a "stomp" causes the slug to
retreat a distance, perhaps stop for a while, and then continue its
march. This reversal can be accomplished by invertor 175 in FIG.
22. The pulse thus turns off power transistor 171, and
simultaneously activates power transistor 179. However, the latter
applies reverse current to the motor, thus driving the slug in
reverse for the duration of pulse 169. With this feature, even if
the slug is within an inch of the goal, the victor in a round is
not necessarily known at that time. A switch 181 on the slug can
select the type of operation, by merely disconnecting power
transistor 179.
Moreover, it is well known how to briefly reverse a motor in
response to a closure of switch 164 in FIG. 27.
Since repeated stompings can cause the slug to veer from its
intended path, it may be desirable to guide the slug along a route.
For example, a clothes line 183 in FIG. 21 can be fed through a
tube in the slug, and tied between heavy books such as 185. The
slug is required to follow the clothes line.
As to the size of the slug, the invading vehicle can have an axle
height of about 15/8 inches. Applicant has experimented by driving
such a vehicle over various books, and has found that books which
are one inch thick present no significant obstacle. Books which are
one and one-half inches thick (ie, which is nearly the distance
from the axle to the ground) present a minor obstacle. Thus, the
slug vehicle can be flat and no taller than the axle height of the
vehicle.
Variations
1. The preceding discussion has assumed that the invading vehicle
wants to avoid mines. However, it may be desired to require the
vehicle to follow a path established by the mines: the invader must
periodically "tag" mines, by getting sufficiently close to trigger
its mine sensors. A simple inversion in the circuitry can
accomplish the required operation. In the inversion, a different
relay is used in place of relay 74 in FIG. 6. The new relay is
biased such that the contact is normally in position 74A, when
transistor 76 is off.
The player must keep the contact out of that position 74A by
keeping the penalty flag 77 HI. That is, during normal operation,
the contact is to be positioned as shown in solid outline, which
connects to "NORMAL MOTOR CONTROL." If the player fails to tag a
mine in time, the penalty flag falls LO and a penalty is imposed:
the contact moves to phantom position 74A.
With no other changes to the circuit, the penalty will persist
forever. In order to restore normal operation after a time
interval, a clock 190 is ORed with the output of one-shot 72, as
shown in phantom. Thus, if there is no output from the one shot 72,
the clock will periodically drive line 73 HI and then LO: a penalty
is imposed, and then normal operation occurs. To maintain normal
operation, the one-shot must be triggered frequently enough that
pulse 77 is maintained. A clock period of five to fifteen seconds
is envisioned. Clearly, the relative durations of the respective
clock and the one-shot pulses will affect the difficulty of the
game, and these durations should be adjustable by the players.
For example, a long clock pulse and a long one-shot pulse will give
the invader an advantage. A long clock pulse and a short one shot
pulse will require frequent tagging, and cause a long penalty when
a required tag is missed. Short clock pulses and short one shot
pulses will requires frequent tagging, and a rapid dash to a mine
to make a tag when a penalty for failure to tag terminates.
After a mine tag fails to occur when required, the contact in relay
74 is pulled to "NORMAL MOTOR CONTROL" the first time the clock 190
goes HI after penalty pulse 77 goes LO. An example will illustrate
this operation.
If a player fails to tag a mine in time to re-trigger the one-shot
72, pulse 77 goes LO, the contact is pulled to position 74A, and a
penalty is imposed. Without clock 190, and without an accidental HI
output from OR gate 70 (as would occur if the penalty caused the
vehicle to accidentally cross a mine), the penalty would persist
forever. Clock 190 prevents this: clock 190 brings line 73 HI
periodically, thus temporarily terminating the penalty and allowing
the player to tag a mine. If the player fails to tag before the
Clock goes LO, the cycle is repeated.
With the requirement of mine-tagging, the defender will, of course,
place the mines as far as possible from the goal as possible. With
this variation, inert mines become highly strategic: the invader
does not know in advance whether a given mine will reset his clock,
until he tries it for the first time. Also, the time display 137 in
FIG. 3 becomes important: the invader wishes to know how much time
he has before needing to run over a mine.
One shot 72 provides a pulse 77 in response to a trigger signal
from OR gate 70. Further, if a trigger signal is received while the
pulse 77 is HI, one pulse duration is added to the pulse at this
time. Consequently, a sequence of triggers from OR gate 70, all
spaced less than one "PENALTY DURATION" apart, keep the relay in
the proper position. Numerous circuits can accomplish this.
2. An oval goal may be used. In this case, when the invader fires
when facing the wide part of the oval, his left- and right aiming
can be inaccurate, and still score a goal. Conversely, when the
invader fires along the narrow axis, his left-right accuracy must
be greater, but his distance can be less accurate. These features
are illustrated in FIG. 23.
3. Cannon velocity, and thus distance fired, can be adjusted by
adjusting the current passing through solenoid 25 in FIG. 4. This
can be done by radio control, thus allowing a player to adjust his
firing range while on a scoring drive.
The cannon can be adjustable in inclination as shown in FIG. 23A,
from horizontal to nearly vertical, and at all angles inbetween.
The user can set the inclination in advance, or a radio-controlled
servo, of the kind used to steer the invading vehicle, can be used,
as shown. With radio-controlled inclination, the range of the
cannon is under control, without adjusting the cannon's electric
power.
4. The magnetic mines can be of the sheet magnet type. These
magnets comprise a plastic matrix, perhaps 1/16 inch thick, into
which iron filings have been embedded. Then, the sheets are
magnetized. It may be desirable to magnetize different regions of
the mines with different polarities, in checkerboard fashion, as in
FIG. 16. Then, when a vehicle crosses the mine, the sensor will
detect the sequence of NSNSNSNSNSNS (ie, north, south, etc).
Sometimes such a sequence is easier to detect using Hall effect
sensors. However, magnetic mines are not essential, as a key
feature is for the vehicle to detect the presence of a specific
object.
5. The stationary cannons 25 in FIGS. 1 and 2 can be controlled by
wires leading to switches for the defender to fire them: they need
not fire at set intervals after loading.
6. It may be desirable to add weights to the balls, in order to
trip the mechanical flags more solidly.
7. The IR gun 23 in FIGS. 1 and 2 can flash off and on, giving a
vehicle a chance to dash past.
8. One form of the invention is an accessory for a pre-existing
radio-controlled vehicle, as shown in FIG. 6. The accessory is
indicated by dashed lines 130. The accessory is interconnected into
the wires which normally control the motors or steering apparatus
of the vehicle. With this accessory, re-design of an entire vehicle
is not necessary. The accessory may fire the vehicle cannon on a
self-timed basis, by including the circuits of FIGS. 4 or 5, or
include a receiver which acts as a remote trigger as discussed
above.
9. It is not necessary that radio control be used. Other types of
remote control can be used, such as optical, or perhaps
acoustical.
10. Several characteristics of PING-PONG balls are important.
First, a flying PING-PONG ball continues to travel after it hits
the ground: the ball can still roll to a target after landing.
Similarly, a PING-PONG ball can be shot along the ground, as a golf
putter shoots a golf ball. Other types of missiles, such as arrows
or darts do not have these characteristics.
Second, PING-PONG balls are spherical; they are blunt. A strike
from even a very fast PING-PONG ball will cause no injury. Such is
not the case with elongated missiles.
Third, PING-PONG balls are very bouncy. This allows the ball to be
shot by an impact. The shooting mechanism can be very compact. For
example, the solenoid described above is only about 1.5 inches long
by about one inch in diameter. In contrast, toy missiles do not
have this bouncy characteristic: they are generally accelerated by
a spring or by a gas discharge.
Fourth, the Inventor has measured a PING-PONG ball and found its
shell to be about 0.015 inches thick and its diameter to be about
1.48 inches. A simple geometric computation shows that the volume
of solid material in the shell is about 0.1 cubic inches (i.e.,
surface area.times.thickness, or 4.times.pi.times.r.sup.2
.times.0.015), and the volume of the ball itself is about 1.69
cubic inches. The packing density is thus 0.1/1.69, or 0.059. This
is the ratio of solid material to air. This particular density,
together with a density up to five times as great (ie, 0.29) is
defined as "substantially hollow." An expanded polyurethane foam
ball can be substantially hollow. A golf ball is not substantially
hollow.
Restated, a ball of the same size as a PING-PONG ball, but five
times heavier, is considered "substantially hollow."
Fifth, PING-PONG balls are not designed for minimal aerodynamic
drag for their mass. They have a constant frontal area, regardless
of orientation: there is no minimal frontal area. In contrast, an
arrow, or aircraft, is designed to be oriented to present a minimal
frontal area to the incoming wind in order to reduce drag.
The balls are fired such that they fly about ten feet. The velocity
acquired is probably less than that acquired by the balls in an
actual game of PING-PONG. This velocity is sufficiently low that
injury to persons or animals is precluded.
11. The invading vehicle can be microprocessor-controlled, which
will provide great flexibility. The collision sensors, which detect
collisions with rovers, encounters with mines, collisions with
PING-PONG balls, and strikes with the IR gun, are fed to the I/O
ports of the microprocessor, either directly, as shown in FIG. 24,
or through the output of an OR gate such as OR gate 70 in FIG. 6.
(In the latter case, the microprocessor cannot distinguish between
types of collisions, since it only receives the OR gate
output.)
One type of flow chart for programming the microprocessor is shown
in FIG. 25. (The dashed boxes are discussed below.) In general, the
microprocessor detects collisions and imposes the appropriate
performance penalty in response. Different types of collision can
cause different penalties, as the Figure indicates. Further, the
penalty for a given type of collision can change. The change can be
random, according to a sequence, or according to a sequence that is
sufficiently complicated that it is effectively random.
For example, the penalties can be A, B, C, and D. A can refer to a
dead stop; B can refer to running in circles, etc. The following
eleven data can be stored in memory locations 100 through 110: A,
A, C, B, D, B, C, D, A, B. When the first collision is detected,
the microprocessor imposes the penalty at address 100; for the
second collision, the penalty at address 101 is used, and so on.
Thus, the panalties are selected from a predetermined sequence. If
the sequence is sufficiently long, then the penalties are, in
effect, randomly selected, since the sequence rarely repeats.
During normal operation, in which mine-tagging is not required, the
steps shown in the dashed boxes 201, 203, 205, 206, and 207 are not
taken: the program proceeds as though the dashed boxes were absent.
During normal operation, the processor cycles through its program
and, if no penalty-inducing events are detected, it simply starts
over. If a penalty event is detected, such as a mine contact, a
penalty is imposed for a time interval, and normal cycling is
resumed.
If mine-tagging is required, then the mine-response step 201A is
different. If a mine is detected, all is well, and dashed box 201
returns the logic to box E. However, if no mine is detected, then
the negative in box 203 takes the logic to inquiry 205. In box 205,
if the time since the last tag of a mine does not exceed the limit,
then box 205 sends the logic to box 206, and the logic recycles
from box E. However, if the time limit is exceeded (that is, the
last tag of a mine was too far in the past), then a mine-type
penalty is imposed by box 208. Then, box 207 re-sets the time clock
within which a mine tag must next occur (because the penalty for
failing to make a tag has just been paid) and the logic returns to
box E. Now, when NO block 203 is next reached, the logic will go to
box 206, since the measured time interval since the last mine tag
has been reset.
The microprocessor allows the players to change the style of play.
For example, switches 300A through 300E in FIG. 24 lead to the I/O
of the microprocessor. Box 209 in FIG. 25 reads the switches. These
switches can be 8-switch DIP's, which send an 8-bit word to the
microprocessor. The eight-bit word allows 256 different messages to
be sent. Switch 300A can send a word indicating how much time is
allowed to the vehicle for making a shot with the PING-PONG ball.
When the time is exceeded, the ball shoots automatically. Setting
this switch is tantamount to setting the RC time constant in FIG.
4.
Switch 300B can select how long the performance penalty should
last. Perhaps only four bits are needed for thias selection. 0000
can indicate 3 seconds, 0001 can indicate 6 seconds, etc.
Switch 300C can select which penalty is used. 0000 can indicate
running in circles is the penalty; 0001 can indicate that
high-speed running in the present direction is the penalty; 1111
can indicate that random penalties are selected; etc.
Switch 300D can activate and de-activate the responses to
collisions. 0000 can indicate that all collisions cause penalties;
0001 can indicate that all collisions except those with magnetic
mines cause penalties; 0011 can indicate that all collisions except
those with mines and rovers cause penalties; 0100 can require
mine-tagging; etc. (If mine-tagging is an option, other switches
should be provided to set the period of clock 190 in FIG. 6, and
the duration of flag 77, as discussed above.)
Switch 300E can select the voltage applied to the cannon's
solenoid, thus changing the range of the cannon. This switch can be
a rotary switch which merely selects different voltages supplied by
several batteries in series, as shown in FIG. 24A.
12. It is not necessary that the PING-PONG cannon shoot the ball
into the air. The cannon can act as a "putter" and knocks the ball
along the ground, like a soccer player, toward targets standing on
the ground, or toward a goal. For example, a bumper 310 on the
vehicle, as in FIG. 26, is triggered by a solenoid (not shown) and
knocks the ball along. With this feature, the vehicle can utilize
the defender's balls which were fired at the vehicle, and left
lying on the field, which adds risk to the defender's shooting.
13. The term "remote control" has been used. This term refers to
control without wires or other mechanical attachment extending
between the vehicle and the operator. This feature allows obstacles
to occupy the path between the player and the vehicle. For example,
the rovers will probably run between the player and his vehicle. A
cable would interfere with the rovers. As another example, a cable
would not allow the vehicle to travel behind a screen 12 in FIG. 1:
the cable would probably knock down the screen. As a still further
example, remote control devices can sent signals for five, ten, and
twenty feet. Expensive devices have a range of 500 yards. Twenty
feet of cable would be extremely cumbersome. More sophisticated
remote control devices can transmit signals for one thousand
feet.
Moreover, remote control, as described above, allows a single
transmitter to control multiple servomechanisms at different
locations. A single transmitter can control several PING-PONG
cannons, a vehicle, the slug, etc. Running wires to each of these
devices, even if the devices are not moving, is time-consuming in
set-up and cumbersome in play.
Further, "remote control" implies approximately real-time control.
Pre-programming of a vehicle is not considered remote control,
although the microprocessor can be pre-programmed in certain
respects, and yet the vehicle is remotely controllable.
14. It may be desirable for the invading vehicle to carry several
cannons, such as a battery of four or six, as shown in FIG. 27A.
Alternately, a single cannon having a magazine holding several
balls can be desirable, as shown in FIG. 27B. PING-PONG guns having
magazines are known in the art. In the former case, all four or six
cannons can be fired either simultaneously, or in sequence.
15. It is not necessary that the components described above be used
in the manner described. For example, one type of play may lie in
each player having a slug, which moves toward the other player's
goal. The slugs respond to ball strikes and to rover strikes.
Rovers randomly stall the slugs by running over them. Meanwhile,
each player shoots balls across the playing field toward the other
player's targets, and toward the rovers, trying to stop the rovers.
When the first slug reaches a goal, points are awarded to the
owner, and the award is modified by the relative difference in
target strikes between the players.
As another example, a single invading vehicle can be used, having
one cannon and a sensor which detects ball strikes. The invader
tries to score a goal, while the defender manually throws balls at
the invader, perhaps by using a PING-PONG paddle to strike the
ball. When the vehicle is hit, it fires the ball, the opportunity
to score is lost, and the defender wins the round.
As a further example, the invading vehicle 3 need not be remotely
controlled, and the goal can be extremely large. The invader loads
the cannon on the vehicle and sets the vehicle off toward the goal.
The defender fires, or throws, PING-PONG balls at the incoming
vehicle. If the defender scores a hit soon enough, the cannon will
fall short of the goal. If not, the cannon will score a goal.
Alternately, the sensor on the invading vehicle can trigger the
cannon, but with a voltage different from the normal voltage. Thus,
perhaps, when the defender strikes the invader, the cannon is
forced to make a very weak shot.
16. It is not necessary that actual action be taken in response to
sensed events. For example, as stated above, sensing of a ball
strike on a vehicle causes the action of a performance penalty.
Also, when the slug vehicle senses contact with the invader, it
takes the action of stopping, or reversing. Instead, a signal can
be produced, possibly causing a light to illiminate. The light
indicates the sensing of the event, and allows a score to be
tallied.
17. The goal toward which the slug vehicle advances can be placed
in a zone where the invader is liable to be struck by the
defender's ball cannons. This positioning will cause the invader to
prefer to stomp the slug early in its progress, because at that
time the invader will be out of range of cannon strikes.
18. There can be two or more goals which the defender must protect,
and the invading vehicle can be equipped with a second type of
weapon, such as a golf ball which he projects along the ground. For
example, in FIG. 28A, the invading vehicle 3 carries a golf ball
356, which is propelled by a solenoid 358. The invading vehicle
drives in as shown in FIG. 30 and launches the golf ball toward a
target vehicle 360 when located at position A. The target vehicle
is under the control of the defender, who must move it from
position 360 to position 360S, in order to avoid being struck. In
so doing, the defender is distracted, and, meanwhile, the invader 3
drives toward the usual goal 33 and fires a PING-PONG ball 29. The
target vehicle can be wire-controlled.
The heavy ball can be fired by a spring-loaded machanism, or by a
solenoid of the type which fires the PING-PONG ball. In addition,
the speed of the vehicle is added to the speed given by the firing
mechanism, so that the heavy ball runs ahead of the vehicle 3, at
least initially.
A heavy ball is used because high inertia is required in order to
roll the distance required to the target vehicle. However, a ball
is not necessary. It is possible that a self-propelled vehicle 375
can be used instead, as shown in FIG. 29. The solenoid 375
activates the attacking vehicle, perhaps gives the attacking
vehicle a small push, and the attaching vehicle drives off under
its own power.
The attacking vehicle can be equipped with a mechanism which causes
it to veer left and right, thus requiring the defender to
constantly monitor it. With this motion, the defender cannot move
his vehicle 360 to a given position and assume that it is safe.
Preferably, the attacking vehicle travels much faster than the
invading vehicle.
It is not necessary that the target for the attacking vehicle or
the heavy ball be a vehicle. Instead, the target may be a large
net, and the defender's vehicle acts to block the attacking
vehicle/ball from the net, like a goalie in ice hockey. In this
case, the defender actually tries to be struck by the attack
vehicle.
A key point is that the invader launches a threat, perhaps as a
mere feint, thereby forcing the defender to take action in response
and partially abandon defense of another goal.
19. An alternate method of shooting a PING-PONG ball is shown in
FIG. 32. A sleeve 402 slides within another sleeve 404 and
compresses a spring 405. A catch 407 rotates about pivot 408, and
is biased against tube 402 by spring 410. A radio-controlled
servo-mechanism 406, of the type identified above, pulls the catch
to the right, and releases sleeve 402, which then strikes the ball
29.
20. An alternate type of play involves a non-controlled vehicle
which senses a strike by a PING-PONG ball, and then (a) stops
temporarily, (b) reverses for a distance and then drives forward,
or (c) suffers some other penalty in response. In play, one player
starts off the vehicle and aims it toward a goal line. The
defending player then tries to stop the vehicle by throwing balls
at it. If the vehicle reaches the goal, the invader wins.
As another alternate, the vehicle described in the preceding
paragraph can be equipped with a PING-PONG ball cannon, which fires
automatically at some time after the attacking player releases the
vehicle. The time interval can be fixed, such as five seconds, or
randomly determined. The object is for the vehicle to successfully
get close enough to the goal line, without being struck by the
defender, so that the ball flies over the goal. For example, if the
ball flies three feet horizontally before it strikes the ground,
then when the vehicle gets within three feet of the goal line, it
will score. Thus, the defender must strike the vehicle before it
reaches the three-foot mark.
When the defender strikes the vehicle, the cannon is either forced
to make its usual shot, or a shot is forced, but at a lesser
voltage, so that the cannon merely dumps the ball and the scoring
drive fails. In the latter case, even after the invading vehicle
passes the three-foot mark, a ball strike can spoil the shot, even
though a goal would be scored if a shot were made. Either or both
of (a) speed of the vehicle and (b) the time interval of cannon
firing should be adjustable, so that the cannon fires as close as
possible to the three-foot mark. In this way, a goal is likely,
while the vehicle is kept away from the defender, who is shooting
from behind the goal line.
In order to make it difficult for the defender to hit the invading
vehicle, the vehicle can alternately veer left- and rightward,
while following a constant centerline. A simple oscillatory motion
in a steering mechanism can accomplish this veering. Generation of
such motion is known in the art.
21. In the situation where mine-tagging is required, the defender
may aim his stationary cannons at the locations where the mines are
placed, because of the likelihood that the invading vehicle will be
there at some time.
Numerous substitutions and modifications can be undertaken without
departing from the true spirit and scope of the invention. What is
desired to be secured by Letters Patent is the invention as defined
in the following claims.
* * * * *